On 09/07/2026 15:55, Heikki Linnakangas wrote:
> On 08/07/2026 22:16, Peter Eisentraut wrote:
>> In pqDrainPending(), there is
>>
>> nread = pqsecure_read(conn, conn->inBuffer + conn->inEnd,
>> bytes_pending);
>> conn->inEnd += nread;
>>
>> But pqsecure_read() can return -1 for error. So adding that to conn-
>> >inEnd at that point seems wrong.
>>
>> There is error handling in the following code, but this would still
>> kind of corrupt the conn->inEnd value?
>>
>> /* When there are bytes pending, the read function is not
>> supposed to fail */
>> if (nread != bytes_pending)
>> {
>> libpq_append_conn_error(conn,
>> "drained only %zu of %zd pending
>> bytes in transport buffer",
>> nread, bytes_pending);
>> return -1;
>> }
>>
>> I'm not sure if that comment means that a -1 return cannot happen? Or
>> just that the whole error check should not happen?
>
> The comment in pgsecure_bytes_pending() says:
>
>> * If pqsecure_read() is called for this number of bytes, it's
>> guaranteed to
>> * return successfully without reading from the underlying socket. See
>> * pqDrainPending() for a more complete discussion of the concepts
>> involved.
>
> so as long as pqsecure_read() and pqsecure_read_pending() honor that
> contract, pqsecure_read() should not return an error. I agree that's a
> bit sloppy though, we should still check the return value.
>
> The intention was also that it cannot do a short read, but that wasn't
> quite clear from the comment either.
>
>> Also note that the format placeholder for nread is wrong. If you do
>> get a -1, it will print some large unsigned value.
>
> Good catch.
>
> Patch attached to clean up all that.
Committed that, and Daniel's #include fix for LibreSSL too.
- Heikki
